CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES
Components for cash, cash equivalents and marketable securities (in millions): | | | | | | | | | | | | | | | | | September 30, 2012 | Cost Basis | | Unrealized Gains | | Unrealized Losses | | Fair Value | Cash | $ | 11.3 |
| | $ | — |
| | $ | — |
| | $ | 11.3 |
| Money market funds and other securities | 16.2 |
| | — |
| | — |
| | 16.2 |
| Cash and cash equivalents | 27.5 |
| | — |
| | — |
| | 27.5 |
| U.S. government and agency securities | 329.5 |
| | 2.5 |
| | — |
| | 332.0 |
| Foreign government bonds | 44.5 |
| | 1.0 |
| | — |
| | 45.5 |
| Asset-back securities | 101.4 |
| | 0.6 |
| | — |
| | 102.0 |
| Mortgage-back securities | 118.2 |
| | 1.2 |
| | (0.1 | ) | | 119.3 |
| Corporate notes and bonds | 530.4 |
| | 9.6 |
| | (0.1 | ) | | 539.9 |
| Municipal securities | 19.3 |
| | 0.1 |
| | — |
| | 19.4 |
| Marketable securities | 1,143.3 |
| | 15.0 |
| | (0.2 | ) | | 1,158.1 |
| Total | $ | 1,170.8 |
| | $ | 15.0 |
| | $ | (0.2 | ) | | $ | 1,185.6 |
|
| | | | | | | | | | | | | | | | | December 31, 2011 | Cost Basis | | Unrealized Gains | | Unrealized Losses | | Fair Value | Cash | $ | 62.1 |
| | $ | — |
| | $ | — |
| | $ | 62.1 |
| Money market funds | 40.1 |
| | — |
| | — |
| | 40.1 |
| Cash and cash equivalents | 102.2 |
| | — |
| | — |
| | 102.2 |
| U.S. government and agency securities | 292.5 |
| | 3.4 |
| | — |
| | 295.9 |
| Foreign government bonds | 24.9 |
| | 0.5 |
| | — |
| | 25.4 |
| Asset-back securities | 58.2 |
| | 0.1 |
| | (0.3 | ) | | 58.0 |
| Mortgage-back securities | 124.1 |
| | 1.1 |
| | (0.3 | ) | | 124.9 |
| Corporate notes and bonds | 518.0 |
| | 7.0 |
| | (2.4 | ) | | 522.6 |
| Municipal securities | 11.8 |
| | 0.1 |
| | — |
| | 11.9 |
| Marketable securities | 1,029.5 |
| | 12.2 |
| | (3.0 | ) | | 1,038.7 |
| Total | $ | 1,131.7 |
| | $ | 12.2 |
| | $ | (3.0 | ) | | $ | 1,140.9 |
|
Activity for marketable securities (in millions): | | | | | | | | | | | | | | | | | | Three Months Ended September 30, | | Nine Months Ended September 30, | | 2012 | | 2011 | | 2012 | | 2011 | Proceeds from sales and maturities | $ | 271.1 |
| | $ | 238.2 |
| | $ | 701.5 |
| | $ | 697.2 |
| Gross realized gains | 2.2 |
| | 2.9 |
| | 5.8 |
| | 6.2 |
| Gross realized losses | 0.4 |
| | 0.3 |
| | 1.2 |
| | 2.0 |
| Other-than-temporary impairments on investments | — |
| | 1.5 |
| | 0.3 |
| | 1.5 |
|
Of the marketable securities on hand at September 30, 2012, 3.7% mature in 2012, 27.1% in 2013, and 69.2% thereafter.
Investments with continuous unrealized losses (in millions): | | | | | | | | | | | | | | | | | | | | | | | | | | Less than 12 months | | Greater than 12 months | | | | | September 30, 2012 | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | Total Fair Value | | Total Unrealized Losses | Mortgage-backed obligations | $ | 32.7 |
| | $ | (0.1 | ) | | $ | 4.3 |
| | $ | — |
| | $ | 37.0 |
| | $ | (0.1 | ) | Corporate notes and bonds | 14.8 |
| | — |
| | 1.3 |
| | (0.1 | ) | | 16.1 |
| | (0.1 | ) | Total | $ | 47.5 |
| | $ | (0.1 | ) | | $ | 5.6 |
| | $ | (0.1 | ) | | $ | 53.1 |
| | $ | (0.2 | ) |
| | | | | | | | | | | | | | | | | | | | | | | | | | Less than 12 months | | Greater than 12 months | | | | | December 31, 2011 | Fair Value | | Unrealized Losses | | Fair Value | | Unrealized Losses | | Total Fair Value | | Total Unrealized Losses | Asset-backed obligations | $ | 31.7 |
| | $ | (0.1 | ) | | $ | 1.1 |
| | $ | (0.2 | ) | | $ | 32.8 |
| | $ | (0.3 | ) | Mortgage-backed obligations | 35.1 |
| | (0.2 | ) | | 1.9 |
| | (0.1 | ) | | 37.0 |
| | (0.3 | ) | Corporate notes and bonds | 137.4 |
| | (2.4 | ) | | 1.0 |
| | — |
| | 138.4 |
| | (2.4 | ) | Total | $ | 204.2 |
| | $ | (2.7 | ) | | $ | 4.0 |
| | $ | (0.3 | ) | | $ | 208.2 |
| | $ | (3.0 | ) |
Unrealized losses from fixed-income securities are primarily attributable to changes in interest rates. Management does not believe any remaining unrealized losses represent other-than-temporary impairments based on our evaluation of available evidence as of September 30, 2012. |